Telephone dial impulsing device



J. F. VADAS TELEPHONE DIAL IMPULSING DEVICE Jan. 5, 1960 Filed Jan. 2, 1959 WINDUP INVENTOR.

JOHN F. VAI) Ain- ATTORNEY UnitedStates Patent O TELEPHONE DIAL IMPULSING DEVICE John F. Vadas, Webster, N.Y., assignor to General I )ynamics Corporation, Rochester, N.Y., a Acorporation of Delaware Application January 2, 1959, Serial No. 784,638

'My invention relates generally to signaling devices, and particularly to the impulsing devices used in telephone dials.

It is the practice to provide a signaling device of the telephone dial type having an indexed, rotatable finger Wheel. The shaft on which the wheel is mounted is journaled to the frame of the dial and is further connected to the frame by a motor spring. The motor spring is effective to urge the shaft and finger wheel to return to a normal position after the wheel has been manually/rotated away from its no'rmal position. An auxiliary, jack shaft, connected to the finger wheel shaft by gears or other means, is linked to a cam used for driving a set of electrical elements, such as a set of impulsing contact springs. A windup operation of the dial is effected by moving the wheel against the force of the motor spring tol the point where a selected one of the indicia coincides with a finger stop attached to the dial frame. A one-way clutch located at some point between the main shaft and the cam is disengaged during the windup operation so that the impulsing contact springs are not driven during the windup operation of the dial. Thereafter, the finger wheel is released from its advanced position so that the dial then carried out its rundown operation under energy provided by the motor spring. The aforementioned clutch is arranged to engage during the rundown operation, so that the cam is rotated during the rundown operation only and drives the aforementio'ned set of Contact springs through a number of operations correlated to the finger wheel index selected in the windup operation.

Asvmentioned, it is necessary to insure that the cam and contact spring set be operated only during the rundown operation in dials of this type, so that the one-way clutches, which may take the form of a friction-actuated do'g coupling the jack shaft to a separately mounted cam, have been supplied on all dials. Such one-way coupling means or clutches are necessarily complex and closely fitted and, accordingly, are expensive to build. In addition, their complex nature offers the disadvantage that they may tend to wear and are easily damaged in use, so that the expected life of telephone dials incorporating suchV clutches has been less than the expected life of the telephone subset o'n which the dial is mounted.

Therefore, it is an object of my invention to provide a new and improved signaling device.

Another object of my invention is to provide a new and improved telephone type dial.

Another object of my inventio'n is to provide a new and improved impulse controlling device for use in signaling devices of the telephone dial type.

Another object of my invention is to provide a new and improved impulse controlling device for use in a telephone dial which does away with the necessity of oneway coupling between the finger wheel and the contact set-controlling cam.

- uI, accomplish these and other objects which will become 2,920,145 Patented Jan. 5, 1960 2 apparent presently in the preferred embodiment of my device, which is described in the following paragraphs. In order to assist the reader in understanding the device set forth in the following description, reference is made to the drawing affixed to' and forming part of the present specification which shows a partially cut-away view of a skeletonized telephone dial.

Referring to the drawing, I provide a dial having frame comprising base member 1 and bridge member 2. Bridge member 2 is fixed in a spaced-apart relationship to member 1 in the manner shown in the drawing by means including spacer member 2a. The frame is provided for mounting the other components included in the dial in the manner next described.

A conventional finger wheel 5 having finger-hole indices equally spaced apart from each other along a portion of the outer edge of wheel 5 is fixed to main shaft 6. Shaft 6 is journaled on frame members 1 and 2, so that wheel 5 and shaft 6 may be rotated with respect to the frame within limits to be set forth. Sleeve 3 is fixed to shaft 6 and lies between frame members 1 and 2. Sleeve 3 serves to retain shaft 6 within the dial frame and to' fix main drive gear 11 concentric with shaft 6 in a plane lying between frame members 1 and 2. Thus, it is seen thatvgear 11 rotates with wheel 5 and shaft 6.A

Motor spring 7 which lies between base member 1 and gear 11 is provided for urging wheel 5 vand shaft 6 to rotate in a clockwise, rundown direction as indicated by the arrow on the periphery of wheel 5. vSpring 7 is formed from fiat stock and is coiled around shaft 6, one end of spring 7 being fixed to frame member 1 and the other end being fixed to shaft 6 by means not shown. Spring 7 is tensioned in order-to propel the assembly including shaft 6 and wheel 5 in the rundown direction until stops (not shown) on shaft 6 and frame member 1 are brought into engagement, a position hereinafter referred to as no'rmaL In order to operate the dial, the finger of the user is inserted into one of the wheel 5 indices from the side of Wheel 5 facing away from frame member 1 and used to rotate wheel 5 in the clockwise, windup direction until the inserted finger engages finger stop member 4, which is also attached to frame member 1 by means not sho'wn. Removal of the users finger from the wheel 5 index at this time releases wheel 5 and shaft 6 so that they return vto' normal under power stored in spring 7 during the windup operation.

I ack shaft 12 is journaled to bearing member 8, which in turn is fixed to bridge member 2. Gear 14, which is fixed to the lower end of shaft 12, which extends into the space between frame member 1 and bridge member 2, is positioned so that the teeth on gear 14 engage the teeth on gear' 11. With this arrangement, shaft 12 is revolved when shaft 6 is rotated in -the above-described manner. The ratio of the number of teeth on gears 11 and 14 is chosen so that shaft 12 is turned through one-half revolution each time wheel 5 is rotated through an angular distance sufficient to bring adjacent ones of the indices on wheel 5 past a single reference point, such as finger stop 4, at the edge of wheel 5.

Having described the basic components of the dial and their operation, I next turn to the description of the impulsing mechanism which is driven by apparatus connected to shaft 12 and wherein my invention lies. Immediately next to the upper end of bearing 8', an enlarged shoulder portion 12a is fixed to shaft 12. Pin 13 extending parallel and eccentric with respect to shaft 12, is fixed to shoulder 12a for purposes to be explained presently.

An impeller comprising cylindrical body portion 14 and blades 15a and 15b is provided to be driven from 3 shaft 12. Shaft 12 passes through a loose-fitting axial opening in impeller body 14, so that the impeller is free to revolve independently of shaft 12 except for the mechanism to be explained below. Each of blades 15a and 15b, which are fixed to opposing points on the side of the impeller body 14, has first and second lifting surfaces which are substantially parallel throughout their extent to each other. Blades 15a and 15b are further positioned on impeller body 14 in a manner such that the aforementioned lifting surfaces are at a fixed pitch with respect to the axis of rotation of impeller body 14 as defined by the axis o'f shaft 12. The aforementioned lifting surfaces of blades 15a and 15b are bounded by top and bottom surfaces lying in common first and second planes, respectively, which are substantially parallel to each other and normal to the axis of rotation of impeller body 14. The top and botto'm surfaces of each of blades 15a and 15b are used as dwells in conjunction with the lifting surfaces of the same blade.

In order to drive the aforementioned impeller from shaft 12, a sector substantially equal to a half section of body member 14 and slightly longer than the length of pin 13 depends from a portion of body member 14. Body member 14 is run onto shaft 12 until the end surface of the depending portion of body member 14 engages the top surface of aforementioned shoulder 12a. Vertical surfaces 22 and 23 formed in body member 14 at the above-described depending portion of body member 14 are engaged by pin 13 when the latter is revolved with shaft 12. With this arrangemnt, lost motion is intro duced between dial finger wheel and the above-described impeller, i.e., when shaft 12 is turned through its first half revolution in the course of the windup operation of the dlal, pin 13, which normally is in engagement with surface 22 of impeller body 14, and shaft 12 pass through one-half revolution before pin 13 engages the surface 23 of impeller body 14. Owing to its inertia, the impeller remains in its normal position until pin 13 engages surface 23. With the above-described arrangement, when finger wheel 5 and shaft 6 have been rotated through an angle equal to the angle separating any two adjacent indices in wheel 5, pin 13 has been advanced into engagement with surface 23, so that further rotation of wheel 5 in the windup direction causes shaft 12 to continue to revolve and to drive the impeller in the clockwise, windup direction indicated in the drawing.

Upon release of the wheel 5 from its operated position, shaft 12 is revolved in the counterclockwise, rundown direction, so that the motion of shaft 12 during its first half revolution of shaft 12 is again lost during the interval that pin 13 is revolved from the point where it engages surface 23 to the point where it engages surface 22 of body member 14. After pin 13 has again engaged surface 22, the impeller is rotated in the counterclockwise, rundown direction until finger wheel 5 is returned to its normal position. The reason for this lost motion will become apparent presently.

In order to translate the above-described windup and rundown motions of the impeller into electrical signals, I provide an assembly which includes a set of electrical elements, such as the contact set including springs 24a and 24b, in combination with means for coupling the impeller to the Contact set. The contact set is used for controlling apparatus including a circuit (not shown) external ,to the dial. Springs 24a and 24b are incorporated yin a conventional flat-spring stack which also includes insulator members 16a and 16b for electrically separating the contact set springs from each other and from the remainder of the dial. Also included in the stack are centering or biasing springs 18a and 1Sb which are located between insulator 16a and bridge member 2 and which are spaced apart from each other by support member 19, whose purpose is yet to be explained. The components of the aforementioned contactl stack are fixed relative to each other and to bridge member 2 of the dial by screws 17 which descend through coincident openings in all stack members and whose ends are tapped into bridge member 2, so that the right-hand ends of springs 2da and 24h are fixed relative to each other.

The free, left-hand end of upper spring 24a overhangs the free end of spring 24h, and is shown electrically connested to spring 24b by contact material at the free ends of the springs when the contact set is in normal condition. The element set may be shifted to its actuated con-` dition and the connection between springs 24a and 24D opened by raising the free end of spring 24a clear of spring 24b by the use of apparatus to be described next.

An actuator member 20 is pivotally joined to support member 19 by pin 25, which extends horizontally through support 19. Actuating member 20 is embraced by the aforementioned biasing springs 18a and 18b, which urge member 20 is in a centered, neutral position. The free end of member 20 can be moved upwardly and downwardly against the tension of springs 18a and 18b, respectively, to opposed, first and second operated positions, respectively. Actuator 20 is restored from either of its operated positions to neutral position by energy supplied from biasing springs 18a and 1Sb. Projecting portion 21M on the free end of member 2f) is separated from the overhanging portion of upper spring 24a when member 2b is in the aforementioned neutral position. When the free end of member 20 is deflected upwardly, portion 20a lifts upper spring 24a clear of spring 24k, thereby changing the contact set from its normal, closed condition to its actuated, open condition. When member 20 is deflected downwardly to its aforementioned first operated position, it is without effect on the contact set.

In order to drive member 20 from the above-described impeller, l provide follower rod 21, which is positioned with respect to the impeller to engage first the midpoint of the upwardand downward-facing lifting surfaces of blades 15a and 15b of the impeller as the latter is revolved under the control of finger wheel 5. Thus, as the impeller assembly is rotated in the windup direction, rod 21 successively is engaged by the downward facing surfaces of blades 15a and 15b, so that member 20 is moved downwardly to its first operated position each time the downward facing working surface of one of blades 15a and 15b engages rod 21. Rod 21 is maintained in the extreme downward position as the lower dwell surface of each of blades 15a and 15b is moved past rod 21. Upon further movement of each impeller blade to the point, where the dwell surface is disengaged from rod 21, actuator 2t) is restored to its neutral position by lower biasing spring 18b. t

During the rundown operation of the dial in which it is desired to impulse springs 24a and 24b, the rotation of the impeller in the previously described manner, brings the upward-facing lifting surface of each of blades 15a and 15b into successive engagement with rod 2l of actuator assembly 20, so that the free end of assembly 20 is moved upwardly to its aforementioned second operated position, where it engages spring 24a and opens the connection between springs 24a and 24b, each time one of blades 15a and 15b is moved into engagement with rod 21. Upon the passage of the upward-facing lifting surface of each of blades 15a and 15b past rod 21, the upper dwell surface of each of blades 15a and 15b is moved into engagement with rod 21, so that contact springs 24a and 24b are maintained in their operated position for this interval. When the upper dwell surface of each of blades 15a and 15b has moved past rod 21, assembly 20` is restored to its neutral position by biasing spring 18a, so that springs 24a and 24b are restored to their normal, closed condition.

In the above-described manner, it is seen that springs 24a and 24b, which are normally electrically joined to-,

gather, are caused to send trains of impulses as the irnpeller is rotated during the rundown operation of the dial.A Owing'to the previously described lost motion in the coupling between shaft 12 and the impeller, the number of impulsing operations of the contact set during each rundown operation is equal to one less than the number of angles equal to the angle defined by adjacent indices on the periphery of finger wheel through which wheel 5 is rotated.

In the embodiment of my invention described above, I having shown an impeller having two blades and an arrangement in which lost motion between shaft 12 and the impeller is equal to one-half revolution of shaft 12. It is to be understood, however, that the number of blades on the impeller can be changed so long as corresponding changes are made in the ratio of the number of the teeth on gears 14 and 11 in order to obtain movement of one blade past rod 21 upon movement of two consecutive indices in wheel 5 past the aforementioned common point and the percentage relationship between the sector depending from impeller body 14 and the entire section of impeller body 14 is revised accordingly.

While I have shown and described the preferred embodiment of my invention, other modifications will readily occur to those skilled in the art. I do not therefore desire my invention to be limited to the specific arrangement shown and described, and I intend in the appended claims to cover all modifications within the spiritl and scope of my invention.

What is claimed is:

1. In an impulsing device, a set of elements operable between normal and actuated conditions, an actuating member movable away from a neutral position to opposed rst and second operated positions, means for urging said actuating member from either operated position into neutral position, said actuating member being disposed with respect to said element set to be operative in response to movement between neutral and second operated positions for driving said element between normal and actuated conditions, respectively, an impeller rotatable about an axis, said impeller having at least one blade including substantially parallel first and second lifting surfaces pitched with respect to the axis of rotation of said impeller, a follower carried by said actuating member disposed to engage said first and said second blade faces upon the rotation of said impeller in first and second opposite directions, respectively, said first and said second blade surfaces being effective in response to the rotation of said impeller for moving said follower and said actuating member between neutral and a first operated position and between neutral and a second operated position, respectively, and means operative for rotating said impeller in first and second directions, whereby said element set remains in normal position during the rotation of said impeller in its first direction and is repeatedly actuated upon the rotation of said impeller in its second direction.

2. The device set forth in claim lk wherein said blade surfaces are bounded by top and bottom surfaces lying substantially parallel to each other and normal to the axis of rotation of said impeller, and said bottom and said top surfaces engage said follower as said impeller is rotated in first and second directions, whereby said element set is maintained in actuated condition during the time said follower is in engagement with said top surface.

3. In a telephone dial for transmitting signals, a set of` rotatable about an axis, each of said blades having substantially parallel first and second working surfaces pitched with respect to the axis of rotation of said impeller, a follower carried by said actuating member disposed to engage said first and said second surfaces of each of said blades during each complete rotation of said impeller in first and second opposite directions, respectively, said rst and said second surfaces of each of said blades being effective in response to the rotationof said impeller in first and second directions for moving said follower and actuating member between neutral and first operated position and between neutral and second operated position, respectively, and means for rotating said impeller in first and second directions, whereby said electrical element set remains in normal condition during the rotation of said impeller in first direction and is repeatedly moved between normal and actuated condition a number of times equal to the number of said impeller blades during each rotation of said impeller in its second direction.

4. The dial set forth in claim 3 wherein each of said blade surfaces are bounded by top and bottom surfaces lying in first and second planes, respectively, which are substantially parallel to each other and normal to the axis of rotation of said impeller, and said bottom and said top surfaces of each of said blades engage said follower as said impeller is rotated in first and second directions, whereby said electrical element set is maintained in actuated condition during the time said follower is in engagement with said top surfaces.

5. In a telephone dial, a set of contact springs, meansv including an impeller rotatable about an axis for driving said springs, a shaft coaxial with said impeller, a pin fixed to and eccentric with respect to the axis of said shaft, a sector-depending from a portion of said impeller disposed for engaging said pin, whereby said shaft may be rotated a fraction of a revolution in first and second opposite directions without moving said impeller.

6. The telephone dial set forth in claim 5 wherein said impeller has an opening passing therethrough coaxial with the axis of rotation of said impeller, and said shaft is loosely received within said impeller in order to fix the axis of rotation of said impeller relative to said shaft.

7. In a telephone dial for transmitting signals, a set of electrical contacts operable between normal and actuated conditions, an actuating member movable away from a neutral position to opposing first and second operated positions, said actuating member being disposed with respect to said elements to be effective in response to movement between neutral and second operated positions for' driving said contact set between normal and actuated conditions, means for urging said actuating member from either operated position to neutral position, an impeller having a plurality of blades rotatable about an axis, each of said blades having substantially parallel first and second working surfaces pitched with respect to the axis of rotation of said impellerand being bounded by top and bottom surfaces lying in first and second planes, respectively, which are substantially parallel to each other and normal to the axis of rotation of said impeller, a follower carried by said actuating member disposed to engage sequentially said first and said bottom surfaces and sequentially engage said second and said top surfaces of each of said blades during each complete rotation of said impeller in first and second opposite directions, respectively, said first and said second surfaces of each of said blades being effective in response to the 4rotation of said impeller in first and second directions for moving said follower and said actuating member between neutral and first operated position and between neutral and second operated position, respectively, a shaft coaxial with said impeller, a pin fixed to and eccentric with respect to the axis of said shaft, a sector depending from a portion of said impeller disposed for engaging said pin, and means including a finger wheel coupled to said shaft for revolvingsaid shaft in rst and ksecond directions, whereby said impeller remains idle during the irst interval of motion of said finger wheel and is thereafter revolved under the control of vsaid finger wheel, and said contact set remains in normal condition during the rotation of said iinger wheel in a windup operation and is repeatedly moved between normal and actuated conditions during the rundown operation of said linger Wheel and is maintained in actuated condition during the time said top surface of each of said blades is in engagement with said follower. 10

8 8. The telephone dial set forth in claim 7 wherein said impeller has an opening passing therethrough coaxial with the axis of rotation of said impeller, and said shaft is loosely received within said impeller, in order to fix the 5 axis of rotation of said impeller relative to said shaft.

Wheeler Aug. 19, 1941 Clarke Aug. 7, 1951 

